Process for the generation of thin inorganic films

ABSTRACT

The present invention is in the field of processes for the generation of thin inorganic films on substrates. In particular, the present invention relates to a process comprising bringing a compound of general formula (I) into the gaseous or aerosol state L m —M—X n  (I) and depositing the compound of general formula (I) from the gaseous or aerosol state onto a solid substrate, wherein R is independent of each other hydrogen, an alkyl group, an alkenyl group, an aryl group or a silyl group, p is 1, 2 or 3, M is Ni or Co, X is a σ-donating ligand which coordinates M, wherein if present at least one X is a ligand which coordinates M via a phosphor or nitrogen atom, m is 1 or 2 and n is 0 to 3.

The present invention is in the field of processes for the generation ofthin inorganic films on substrates, in particular atomic layerdeposition processes.

With the ongoing miniaturization, e.g. in the semiconductor industry,the need for thin inorganic films on substrates increases while therequirements of the quality of such films become stricter.

Thin inorganic films serve different purposes such as barrier layers,dielectrica, conducting features, capping, or separation of finestructures. Several methods for the generation of thin inorganic filmsare known. One of them is the deposition of film forming compounds fromthe gaseous state on a substrate. In order to bring metal atoms into thegaseous state at moderate temperatures, it is necessary to providevolatile precursors, e.g. by complexation the metals with suitableligands. These ligands need to be removed after deposition of thecomplexed metals onto the substrate.

Metal complexes for gas phase deposition are known from prior art. WO2008/142 653 as well as U.S. Pat. No. 5,130,172 disclose hexadienylcobalt complexes with π-donating ligands, such as cyclopentadienyl.However, films obtained with such compounds contain a considerableamount of residual carbon which is undesirable in many cases.

Rinze discloses in the Journal of Organometallic Chemistry, volume 77(1974), on pages 259-264 cycloheptadienyl cobalt complexes withtriarylphosphane coligands. However, no information about suitability invapor deposition processes is given.

It was an object of the present invention to provide a process for thegeneration of thin inorganic films with lower residual carbon content.Furthermore, it was aimed at a process employing compounds which can besynthesized and handled more easily. The process should also be flexiblewith regard to parameters such as temperature or pressure in order to beadaptable to various different applications.

These objects were achieved by a process comprising bringing a compoundof general formula (I) into the gaseous or aerosol state

and depositing the compound of general formula (I) from the gaseous oraerosol state onto a solid substrate, wherein

R is independent of each other hydrogen, an alkyl group, an alkenylgroup, an aryl group or a silyl group,

p is 1, 2 or 3,

M is Ni or Co,

X is a σ-donating ligand which coordinates M, wherein if present atleast one X is a ligand which coordinates M via a phosphor or nitrogenatom,

m is 1 or 2 and

n is 0 to 3.

The present invention further relates to a compound of general formula(I), wherein

R is independent of each other hydrogen, an alkyl group, an alkenylgroup, an aryl group or a silyl group,

p is 1, 2 or 3,

M is Ni or Co,

X is a σ-donating ligand which coordinates M, wherein if present atleast one X is a trialkylphosphane or a ligand which coordinates M via anitrogen atom,

m is 1 or 2 and

n is 0 to 3.

The present invention further relates to use of a compound of generalformula (I), wherein

R is independent of each other hydrogen, an alkyl group, an alkenylgroup, an aryl group or a silyl group,

p is 1, 2 or 3,

M is Ni or Co,

X is a σ-donating ligand which coordinates M, wherein if present atleast one X is a ligand which coordinates M via a phosphor or nitrogenatom,

m is 1 or 2 and

n is 0 to 3,

for a film formation process.

Preferred embodiments of the present invention can be found in thedescription and the claims. Combinations of different embodiments fallwithin the scope of the present invention.

The ligands L is an anionic ligand which typically means that the ligandis an anion before coordinating to M. Sometimes, the delocalization ofthe charge is reflected in the formula, which then becomes generalformula (I′).

However, neither general formula (I) nor (I′) is intended to define howthe ligand L coordinates to M. It is, for example, possible that Lcoordinates via a η¹, a η³ or a η⁵ bond to M. Without being bound by anytheory, it is believed that the other ligand or ligands X have aninfluence on how L is coordinated to M. The ligand L is often referredto as a cyclohexadienyl, a cycloheptadienyl, or a cyclooctadienylderivative.

In the compound of general formula (I) R is independent of each otherhydrogen, an alkyl group, an alkenyl group, an aryl group or a silylgroup, preferably hydrogen, an alkyl or silyl group, in particularhydrogen. It is possible that all R are the same, or that some R are thesame and the remaining R are different therefrom or that all R aredifferent to each other. Preferably, all R are the same.

An alkyl group can be linear or branched. Examples for a linear alkylgroup are methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl,n-octyl, n-nonyl, n-decyl. Examples for a branched alkyl group areiso-propyl, iso-butyl, sec-butyl, tert-butyl, 2-methyl-pentyl,2-ethyl-hexyl, cyclo-propyl, cyclohexyl, indanyl, norbornyl. Preferably,the alkyl group is a C₁ to C₈ alkyl group, more preferably a C₁ to C₆alkyl group, in particular a C₁ to C₄ alkyl group, such as methyl,ethyl, iso-propyl or tert-butyl. Alkyl groups can be substituted, forexample by halogens such as F, Cl, Br, I, in particular F; by hydroxylgroups; by ether groups; or by amines such as dialkylamines.

An alkenyl group contains at least one carbon-carbon double bond. Thedouble bond can include the carbon atom with which the alkenyl group isbound to the rest of the molecule, or it can be placed further away fromthe place where the alkenyl group is bound to the rest of the molecule,preferably it is placed further away from the place where the alkenylgroup is bound to the rest of the molecule. Alkenyl groups can be linearor branched. Examples for linear alkenyl groups in which the double bondincludes the carbon atom with which the alkenyl group is bound to therest of the molecule include 1-ethenyl, 1-propenyl, 1-n-butenyl,1-n-pentenyl, 1-n-hexenyl, 1-n-heptenyl, 1-n-octenyl. Examples forlinear alkenyl groups in which the double bond is placed further awayfrom the place where alkenyl group is bound to the rest of the moleculeinclude 1-n-propen-3-yl, 2-buten-1-yl, 1-buten-3-yl, 1-buten-4-yl,1-hexen-6-yl. Examples for branched alkenyl groups in which the doublebond includes the carbon atom with which alkenyl group is bound to therest of the molecule include 1-propen-2-yl, 1-n-buten-2-yl,2-buten-2-yl, cyclopenten-1-yl, cyclohexen-1-yl. Examples for branchedalkenyl groups in which the double bond is placed further away from theplace where alkenyl group is bound to the rest of the molecule include2-methyl-1-buten-4-yl, cyclopenten-3-yl, cyclohexene-3-yl. Examples foran alkenyl group with more than one double bonds include1,3-butadien-1-yl, 1,3-butadien-2-yl, cylopentadien-5-yl.

Aryl groups include aromatic hydrocarbons such as phenyl, naphthalyl,anthrancenyl, phenanthrenyl groups and heteroaromatic groups such aspyrryl, furanyl, thienyl, pyridinyl, quinoyl, benzofuryl,benzothiophenyl, thienothienyl. Several of these groups or combinationsof these groups are also possible like biphenyl, thienophenyl orfuranylthienyl. Aryl groups can be substituted for example by halogenslike fluoride, chloride, bromide, iodide; by pseudohalogens likecyanide, cyanate, thiocyanate; by alcohols; alkyl chains or alkoxychains. Aromatic hydrocarbons are preferred, phenyl is more preferred.

A silyl group is a silicon atom with typically three substituents.Preferably a silyl group has the formula SiE₃, wherein E is independentof each other hydrogen, an alkyl group, an alkenyl group, an aryl groupor a silyl group. It is possible that all three E are the same or thattwo E are the same and the remaining E is different or that all three Eare different to each other. It is also possible that two E togetherform a ring including the Si atom. Alkyl and aryl groups are asdescribed above. Examples for siliyl groups include SiH₃, methylsilyl,trimethylsilyl, triethylsilyl, tri-n-propylsilyl, tri-iso-propylsilyl,tricyclohexylsilyl, dimethyl-tert-butylsilyl, dimethylcyclohexylsilyl,methyl-di-iso-propylsilyl, triphenylsilyl, phenylsilyl,dimethylphenylsilyl, pentamethyldisilyl.

Generally, sp³ carbon atoms in the compound of general formula (I) canbe replaced by silicon atoms. Therefore, the compound of general formula(I) can be the more general formula (Ia)

wherein A is CR₂ or SiR₂, wherein the same definition for R as describedabove applies including the fact that the two R can be the same ordifferent to each other. If p is 2 or 3, the two or three A can be thesame or different to each other. Usually, at most one A is SiR₂ and theremaining A are CR₂.

According to the present invention, M is Ni or Co, i.e. nickel orcobalt. M can be in various oxidation states. Preferably, M is Ni in theoxidation state +2 or Co in the oxidation state +1.

According to the present invention, the ligand X in the compound ofgeneral formula (I) can be any σ-donating ligand which coordinates M,wherein if present at least one X is a ligand which coordinates M via aphosphor or nitrogen atom. In the context of the present invention, anyligand which forms a σ-bond to M thereby providing at least oneelectron, for example an electron pair, to M is regarded as σ-donatingligand irrespective of whether any further bond can be formed to M or isactually formed. If n is 2 or 3, i.e. the compound of general formula(I) contains two or three X, the two or three X can be the same ordifferent to each other. If they are different to each other, the otherX can be any σ-donating ligand which coordinates M. Any or all X can bein any ligand sphere of M, e.g. in the inner ligand sphere, in the outerligand sphere, or only loosely associated to M. Preferably, X is in theinner ligand sphere of M.

X can be a ligand which coordinates M via a nitrogen atom, for exampleamines like trimethylamine, triphenylamine, dimethylamino-iso-propanol;ethylenediamine derivatives like N,N,N′,N′-tetramethylethylenediamine orN,N,N′,N″,N″-pentamethyldiethylenetriamine; imines like2,4-pentandione-N-alkylimines, 2,4-pentandione-N-iso-propylimine,glyoxal-N,N′-bis-isopropyl-diimine, glyoxal-N,N′-bis-tert-butyl-diimineor 2,4-pentanedione-diimine; diketiminates such asN,N′-2,4-pentanediketiminate; iminopyrroles includingpyrrol-2-carbald-alkylimines such as pyrrol-2-carbald-ethylimine,pyrrol-2-carbald-iso-propylimine or pyrrol-2-carbald-tert-butylimine aswell as pyrrol-2,5-biscarbald-alkyldiimines such aspyrrol-2,5-biscarbald-tert-butyldiimine; amidinates such as acetamidineor N,N′-bis-iso-propylacetamidine; guanidinates such as guanidine;aminoimines such as2-N-tert-butylamino-2-methylpropanal-N-tertbuylimine; amides such asformamide or acetamide.

X can also be a ligand which coordinates M via a phosphor atom includingphosphane or trisubstituted phosphanes including trihalogenphosphanes,trialkylphosphanes, dialkylarylphosphanes, alkyl-diarylphosphanes ortriarylphosphanes, wherein the alkyl or the aryl groups can be the sameor different to each other if more than one alkyl or aryl group ispresent.

Examples include trifluoro phosphane, trimethyl phosphane,trimethoxyphosphane, methyl-dimethoxy phosphane, tri-tertbutylphosphane, tricyclohexyl phosphane, di-isopropyl-tert-butyl phosphane,dimethyl-tert-butyl phosphane, triphenyl phosphane, andtritolylphosphane. It is also possible that X which coordinates via aphosphor atom contains two or more phosphor atoms. Such compoundsinclude diphosphinoethanes such as 1,2-bis(diethylphosphino)ethane.

If more than one ligand X is present, the other X can be any ligandwhich is a σ-donating ligand which coordinates M including neutral oranionic ligands. Examples for anionic ligands X include halogens likefluoride, chloride, bromide or iodide; pseudohalogens like cyanide,isocyanide, cyanate, isocyanate, thiocyanate, isothiocyanate, or azide;alkyl anions like methyl, ethyl, butyl, or neopentyl anions as well assilicon bearing alkyl groups such as trimethylsilyl methyl; hydride;alkanolates like methanolate, ethanolate, iso-propanolate,tert-butanolate; acetylacetonate or its derivatives such as1,1,1,5,5,5-pentafluoroacetylacetonate; amine anions like dimethylamide,hexamethyldisilazide, or trimethylsilyl tert.-butyl amide.

Neutral ligands include ligands which coordinates M via a phosphor ornitrogen atom. Further examples for neutral ligands X include nitricoxide (NO) or carbonmonoxide (CO).

Preferably, in the compound of general formula (I), M is Co in theoxidation state +1, m is 1, and all X are neutral. In this case it ispossible that the compound of general formula (I) contains one neutralligands X, i.e. n is 1, or two or three, preferably two. Alsopreferably, M is Ni in the oxidation state +2, m is 2, and n is 0. Inanother preferred example, M is Ni in the oxidation state +2, m is 1, nis 2, wherein one X is anionic and one is neutral.

It is preferred that the molecular weight of the compound of generalformula (I) is up to 1000 g/mol, more preferred up to 800 g/mol, inparticular up to 600 g/mol.

Some preferred examples for compounds of general formula (Ia) are givenin the following table.

No. R A p m M X n C-1 H C(CH₃)₂ 1 2 Ni — 0 C-2 H Si(CH₃)₂ 1 2 Ni — 0 C-3H CH₂ 2 2 Ni — 0 C-4 H CH₂ 3 2 Ni — 0 C-5 H C(CH₃)₂ 1 1 Ni N(CHMe₂)₂ 1C-6 H C(CH₃)₂ 1 1 Ni N(CMe₃)₂ 1 C-7 H C(CH₃)₂ 1 1 Ni N(C₆H₅)₂ 1 C-8 HC(CH₃)₂ 1 1 Ni N(SiMe₃)₂ 1 C-9 H C(CH₃)₂ 1 1 Ni P^(t)Bu₃ 1 C-10 H CH₂ 21 Ni N(CHMe₂)₂ 1 C-11 H CH₂ 2 1 Ni N(CMe₃)₂ 1 C-12 H CH₂ 2 1 Ni N(C₆H₅)₂1 C-13 H CH₂ 2 1 Ni N(SiMe₃)₂ 1 C-14 H CH₂ 2 1 Ni P^(t)Bu₃ 1 C-15 H CH₂3 1 Ni N(CHMe₂)₂ 1 C-16 H CH₂ 3 1 Ni N(CMe₃)₂ 1 C-17 H CH₂ 3 1 NiN(C₆H₅)₂ 1 C-18 H CH₂ 3 1 Ni N(SiMe₃)₂ 1 C-19 H CH₂ 3 1 Ni P^(t)Bu₃ 1C-20 H Si(CH₃)₂ 1 1 Ni N(CHMe₂)₂ 1 C-21 H Si(CH₃)₂ 1 1 Ni N(CMe₃)₂ 1C-22 H Si(CH₃)₂ 1 1 Ni N(C₆H₅)₂ 1 C-23 H Si(CH₃)₂ 1 1 Ni N(SiMe₃)₂ 1C-24 H Si(CH₃)₂ 1 1 Ni P^(t)Bu₃ 1 C-25 H C(CH₃)₂ 1 1 Co PMe₃ 2 C-26 HC(CH₃)₂ 1 1 Co PMe₃ 3 C-27 H C(CH₃)₂ 1 1 Co PF₃ 2 C-28 H C(CH₃)₂ 1 1 CoPF₃ 3 C-29 H C(CH₃)₂ 1 1 Co PMe₃ 2 CO C-30 H C(CH₃)₂ 1 1 Co PMe₃ 3 CO COC-31 H C(CH₃)₂ 1 1 Co PMe₃ 3 PMe₃ CO C-32 H C(CH₃)₂ 1 1 Co PEt₃ 2 C-33 HC(CH₃)₂ 1 1 Co PEt₃ 3 C-32 H C(CH₃)₂ 1 1 Co depe 1 C-33 H C(CH₃)₂ 1 1 Codepe 2 PMe₃ C-34 H C(CH₃)₂ 1 1 Co tmeda 1 C-35 H CH₂ 2 1 Co PMe₃ 2 C-36H CH₂ 2 1 Co PMe₃ 3 C-37 H CH₂ 2 1 Co PF₃ 2 C-38 H CH₂ 2 1 Co PF₃ 3 C-39H CH₂ 2 1 Co PMe₃ 2 CO C-40 H CH₂ 2 1 Co PMe₃ 3 CO CO C-41 H CH₂ 2 1 CoPMe₃ 3 PMe₃ CO C-42 H CH₂ 2 1 Co PEt₃ 2 C-43 H CH₂ 2 1 Co PEt₃ 3 C-44 HCH₂ 2 1 Co depe 1 C-45 H CH₂ 2 1 Co depe 2 PMe₃ C-46 H CH₂ 2 1 Co depe 2CO C-47 H CH₂ 2 1 Co tmeda 1 C-48 H CH₂ 3 1 Co PMe₃ 2 C-49 H CH₂ 3 1 CoPMe₃ 3 C-50 H CH₂ 3 1 Co PF₃ 2 C-51 H CH₂ 3 1 Co PF₃ 3 C-52 H CH₂ 3 1 CoPMe₃ 2 CO C-53 H CH₂ 3 1 Co PMe₃ 3 CO CO C-54 H CH₂ 3 1 Co PMe₃ 3 PMe₃CO C-55 H CH₂ 3 1 Co PEt₃ 2 C-56 H CH₂ 3 1 Co PEt₃ 3 C-57 H CH₂ 3 1 Codepe 1 C-58 H CH₂ 3 1 Co depe 2 PMe₃ C-59 H CH₂ 3 1 Co depe 2 CO C-60 HCH₂ 3 1 Co tmeda 1 C-61 H Si(CH₃)₂ 1 1 Co PMe₃ 2 C-62 H Si(CH₃)₂ 1 1 CoPMe₃ 3 C-63 H Si(CH₃)₂ 1 1 Co PF₃ 2 C-64 H Si(CH₃)₂ 1 1 Co PF₃ 3 C-65 HSi(CH₃)₂ 1 1 Co PMe₃ 2 CO C-66 H Si(CH₃)₂ 1 1 Co PMe₃ 3 CO CO C-67 HSi(CH₃)₂ 1 1 Co PMe₃ 3 PMe₃ CO C-68 H Si(CH₃)₂ 1 1 Co PEt₃ 2 C-69 HSi(CH₃)₂ 1 1 Co PEt₃ 3 C-70 H Si(CH₃)₂ 1 1 Co depe 1 C-71 H Si(CH₃)₂ 1 1Co depe 2 PMe₃ C-72 H Si(CH₃)₂ 1 1 Co depe 2 CO C-73 H Si(CH₃)₂ 1 1 Cotmeda 1 C-74 H CH₂ 3 1 Co dmpe 2 PMe₃ C-75 H CH₂ 3 1 Co dmpe 2 CO

PMe₃ stands for trimethylphosphane, P^(t)Bu₃ fortri-(tert-butyl)phosphine, PEt₃ for triethylphosphane, depe for1,2-bis(diethylphosphino)ethane, tmeda forN,N,N′,N′-tetramethylethylenediamine, and dmpe for1,2-bis(dimethylphosphino)ethane.

The compound of general formula (I) used in the process according to thepresent invention is preferably used at high purity to achieve bestresults. High purity means that the substance employed contains at least90 wt.-% compound of general formula (I), preferably at least 95 wt.-%compound of general formula (I), more preferably at least 98 wt.-%compound of general formula (I), in particular at least 99 wt.-%compound of general formula (I). The purity can be determined byelemental analysis according to DIN 51721 (Prüfung festerBrennstoffe—Bestimmung des Gehaltes an Kohlenstoff undWasserstoff—Verfahren nach Radmacher-Hoverath, August 2001).

In the process according to the present invention the compound ofgeneral formula (I) is brought into the gaseous or aerosol state. Thiscan be achieved by heating the compound of general formula (I) toelevated temperatures. In any case a temperature below the decompositiontemperature of the compound of general formula (I) has to be chosen.Preferably, the heating temperature ranges from slightly above roomtemperature to 300° C., more preferably from 30° C. to 250° C., evenmore preferably from 40° C. to 200° C., in particular from 50° C. to150° C.

Another way of bringing the compound of general formula (I) into thegaseous or aerosol state is direct liquid injection (DLI) as describedfor example in US 2009/0 226 612 A1. In this method the compound ofgeneral formula (I) is typically dissolved in a solvent and sprayed in acarrier gas or vacuum. Depending on the vapor pressure of the compoundof general formula (I), the temperature and the pressure the compound ofgeneral formula (I) is either brought into the gaseous state or into theaerosol state. Various solvents can be used provided that the compoundof general formula (I) shows sufficient solubility in that solvent suchas at least 1 g/l, preferably at least 10 g/l, more preferably at least100 g/l. Examples for these solvents are coordinating solvents such astetrahydrofuran, dioxane, diethoxyethane, pyridine or non-coordinatingsolvents such as hexane, heptane, benzene, toluene, or xylene. Solventmixtures are also suitable. The aerosol comprising the compound ofgeneral formula (I) should contain very fine liquid droplets or solidparticles. Preferably, the liquid droplets or solid particles have aweight average diameter of not more than 500 nm, more preferably notmore than 100 nm. The weight average diameter of liquid droplets orsolid particles can be determined by dynamic light scattering asdescribed in ISO 22412:2008. It is also possible that a part of thecompound of general formula (I) is in the gaseous state and the rest isin the aerosol state, for example due to a limited vapor pressure of thecompound of general formula (I) leading to partial evaporation of thecompound of general formula (I) in the aerosol state.

Alternatively, the metal-containing compound can be brought into thegaseous state by direct liquid evaporation (DLE) as described forexample by J. Yang et al. (Journal of Materials Chemistry C, volume 3(2015) page 12098-12106). In this method, the metal-containing compoundor the reducing agent is mixed with a solvent, for example a hydrocarbonsuch as tetradecane, and heated below the boiling point of the solvent.By evaporation of the solvent, the metal-containing compound or thereducing agent is brought into the gaseous state. This method has theadvantage that no particulate contaminants are formed on the surface.

It is preferred to bring the compound of general formula (I) into thegaseous or aerosol state at decreased pressure. In this way, the processcan usually be performed at lower heating temperatures leading todecreased decomposition of the compound of general formula (I).

It is also possible to use increased pressure to push the compound ofgeneral formula (I) in the gaseous or aerosol state towards the solidsubstrate. Often, an inert gas, such as nitrogen or argon, is used ascarrier gas for this purpose. Preferably, the pressure is 10 bar to 10⁻⁷mbar, more preferably 1 bar to 10⁻³ mbar, in particular 10 to 0.1 mbar,such as 1 mbar.

In the process according to the present invention a compound of generalformula (I) is deposited on a solid substrate from the gaseous oraerosol state. The solid substrate can be any solid material. Theseinclude for example metals, semimetals, oxides, nitrides, and polymers.It is also possible that the substrate is a mixture of differentmaterials. Examples for metals are tantalum, tungsten, cobalt, nickel,platinum, ruthenium, palladium, manganese, aluminum, steel, zinc, andcopper. Examples for semimetals are silicon, germanium, and galliumarsenide. Examples for oxides are silicon dioxide, titanium dioxide,zirconium oxide, and zinc oxide. Examples for nitrides are siliconnitride, aluminum nitride, titanium nitride, tantalum nitride andgallium nitride. Examples for polymers are polyethylene terephthalate(PET), polyethylene naphthalenedicarboxylic acid (PEN), and polyamides.

The solid substrate can have any shape. These include sheet plates,films, fibers, particles of various sizes, and substrates with trenchesor other indentations. The solid substrate can be of any size. If thesolid substrate has a particle shape, the size of particles can rangefrom below 100 nm to several centimeters, preferably from 1 μm to 1 mm.In order to avoid particles or fibers to stick to each other while thecompound of general formula (I) is deposited onto them, it is preferablyto keep them in motion. This can, for example, be achieved by stirring,by rotating drums, or by fluidized bed techniques.

The deposition takes place if the substrate comes in contact with thecompound of general formula (I). Generally, the deposition process canbe conducted in two different ways: either the substrate is heated aboveor below the decomposition temperature of the compound of generalformula (I). If the substrate is heated above the decompositiontemperature of the compound of general formula (I), the compound ofgeneral formula (I) continuously decomposes on the surface of the solidsubstrate as long as more compound of general formula (I) in the gaseousor aerosol state reaches the surface of the solid substrate. Thisprocess is typically called chemical vapor deposition (CVD). Usually, aninorganic layer of homogeneous composition, e.g. the metal oxide ornitride, is formed on the solid substrate as the organic material isdesorbed from the metal M. Typically the solid substrate is heated to atemperature in the range of 300 to 1000° C., preferably in the range of350 to 600° C.

Alternatively, the substrate is below the decomposition temperature ofthe compound of general formula (I). Typically, the solid substrate isat a temperature equal to or lower than the temperature of the placewhere the compound of general formula (I) is brought into the gaseous oraerosol state, often at room temperature or only slightly above.Preferably, the temperature of the substrate is at least 30° C. lowerthan the place where the compound of general formula (I) is brought intothe gaseous or aerosol state. Preferably, the temperature of thesubstrate is from room temperature to 400° C., more preferably from 100to 300° C., such as 150 to 220° C.

The deposition of compound of general formula (I) onto the solidsubstrate is either a physisorption or a chemisorption process.Preferably, the compound of general formula (I) is chemisorbed on thesolid substrate. One can determine if the compound of general formula(I) chemisorbs to the solid substrate by exposing a quartz microbalancewith a quartz crystal having the surface of the substrate in question tothe compound of general formula (I) in the gaseous or aerosol state. Themass increase is recorded by the eigen frequency of the quartz crystal.Upon evacuation of the chamber in which the quartz crystal is placed themass should not decrease to the initial mass, but about a monolayer ofthe residual compound of general formula (I) remains if chemisorptionhas taken place. In most cases where chemisorption of the compound ofgeneral formula (I) to the solid substrate occurs, the X-rayphotoelectron spectroscopy (XPS) signal (ISO 13424 EN—Surface chemicalanalysis—X-ray photoelectron spectroscopy—Reporting of results ofthin-film analysis; October 2013) of M changes due to the bond formationto the substrate.

If the temperature of the substrate in the process according to thepresent invention is kept below the decomposition temperature of thecompound of general formula (I), typically a monolayer is deposited onthe solid substrate. Once a molecule of general formula (I) is depositedon the solid substrate further deposition on top of it usually becomesless likely. Thus, the deposition of the compound of general formula (I)on the solid substrate preferably represents a self-limiting processstep. The typical layer thickness of a self-limiting depositionprocesses step is from 0.01 to 1 nm, preferably from 0.02 to 0.5 nm,more preferably from 0.03 to 0.4 nm, in particular from 0.05 to 0.2 nm.The layer thickness is typically measured by ellipsometry as describedin PAS 1022 DE (Referenzverfahren zur Bestimmung von optischen unddielektrischen Materialeigenschaften sowie der Schichtdicke dünnerSchichten mittels Ellipsometrie; February 2004).

Often it is desired to build up thicker layers than those justdescribed. In order to achieve this in the process according to thepresent invention it is preferable to decompose the deposited compoundof general formula (I) by removal of all ligands after which furthercompound of general formula (I) is deposited. This sequence ispreferably performed at least twice, more preferably at least 10 times,in particular at least 50 times. Removing all ligands in the context ofthe present invention means that at least 95 wt.-% of the total weightof the ligands in the deposited compound of general formula (I) areremoved, preferably at least 98 wt.-%, in particular at least 99 wt.-%.The decomposition can be effected in various ways. The temperature ofthe solid substrate can be increased above the decompositiontemperature.

Furthermore, it is possible to expose the deposited compound of generalformula (I) to a plasma like an oxygen plasma or a hydrogen plasma; tooxidants like oxygen, oxygen radicals, ozone, nitrous oxide (N₂O),nitric oxide (NO), nitrogendioxde (NO₂) or hydrogenperoxide; to reducingagents like hydrogen, alcohols, hydroazine or hydroxylamine; or solventslike water. It is preferable to use oxidants, plasma or water to obtaina layer of a metal oxide. Exposure to water, an oxygen plasma or ozoneis preferred. Exposure to water is particularly preferred. If layers ofelemental metal are desired it is preferable to use reducing agents.Preferred examples are hydrogen, hydrogen radicals, hydrogen plasma,ammonia, ammonia radicals, ammonia plasma, hydrazine,N,N-dimethylhydrazine, silane, disilane, trisilane, cyclopentasilane,cyclohexasilane, dimethylsilane, diethylsilane, or trisilylamine; morepreferably hydrogen, hydrogen radicals, hydrogen plasma, ammonia,ammonia radicals, ammonia plasma, hydrazine, N,N-dimethylhydrazine,silane; in particular hydrogen. The reducing agent can either directlycause the decomposition of the deposited compound of general formula (I)or it can be applied after the decomposition of the deposited compoundof general formula (I) by a different agent, for example water. Forlayers of metal nitrides it is preferable to use ammonia or hydrazine.Typically, a low decomposition time and high purity of the generatedfilm is observed.

A deposition process comprising a self-limiting process step and asubsequent self-limiting reaction is often referred to as atomic layerdeposition (ALD). Equivalent expressions are molecular layer deposition(MLD) or atomic layer epitaxy (ALE). Hence, the process according to thepresent invention is preferably an ALD process. The ALD process isdescribed in detail by George (Chemical Reviews 110 (2010), 111-131).

A particular advantage of the process according to the present inventionis that the compound of general formula (I) is very versatile, so theprocess parameters can be varied in a broad range. Therefore, theprocess according to the present invention includes both a CVD processas well as an ALD process.

Depending on the number of sequences of the process according to thepresent invention performed as ALD process, films of various thicknessesare generated. Preferably, the sequence of depositing the compound ofgeneral formula (I) onto a solid substrate and decomposing the depositedcompound of general formula (I) is performed at least twice. Thissequence can be repeated many times, for example 10 to 500, such as 50or 100 times. Usually, this sequence is not repeated more often than1000 times. Ideally, the thickness of the film is proportional to thenumber of sequences performed. However, in practice some deviations fromproportionality are observed for the first 30 to 50 sequences. It isassumed that irregularities of the surface structure of the solidsubstrate cause this non-proportionality.

One sequence of the process according to the present invention can takefrom milliseconds to several minutes, preferably from 0.1 second to 1minute, in particular from 1 to 10 seconds. The longer the solidsubstrate at a temperature below the decomposition temperature of thecompound of general formula (I) is exposed to the compound of generalformula (I) the more regular films formed with less defects.

The present invention also relates to a compound of general formula (I).The same definitions and preferred embodiments as described for theprocess apply.

It has been observed that when a Co(II) source is reacted with at leasttwo equivalents of the anionic ligand L, two ligands L are oxidativelycoupled to form dimeric complexes of general formula (II).

X, n, R, A, and p have the same meaning as for the compound of generalformula (I). G is a neutral, covalently bound dimer of ligand L. As thecompound of general formula (II) is a good starting point for thesynthesis of the compound of general formula (I) in which M is Co, thepresent invention also relates to the compound of general formula (II).Some examples for compounds of general formula (II) are given in thefollowing table.

No. R A p M G X n C-II-1 H CH₂ 2 Co G¹ — 0 C-II-2 H C(CH₃)₂ 1 Co G² — 0C-II-3 H CH₂ 3 Co G³ — 0 C-II-4 H Si(CH₃)₂ 1 Co G⁴ — 0

G¹ to G⁴ have the following meaning.

The process according to the present invention yields a film. A film canbe only one monolayer of deposited compound of formula (I), severalconsecutively deposited and decomposed layers of the compound of generalformula (I), or several different layers wherein at least one layer inthe film was generated by using the compound of general formula (I). Afilm can contain defects like holes. These defects, however, generallyconstitute less than half of the surface area covered by the film. Thefilm is preferably an inorganic film. In order to generate an inorganicfilm, all organic ligands have to be removed from the film as describedabove. More preferably, the film is an elemental metal film. The filmcan have a thickness of 0.1 nm to 1 μm or above depending on the filmformation process as described above. Preferably, the film has athickness of 0.5 to 50 nm. The film preferably has a very uniform filmthickness which means that the film thickness at different places on thesubstrate varies very little, usually less than 10%, preferably lessthan 5%. Furthermore, the film is preferably a conformal film on thesurface of the substrate. Suitable methods to determine the filmthickness and uniformity are XPS or ellipsometry.

The film obtained by the process according to the present invention canbe used in an electronic element. Electronic elements can havestructural features of various sizes, for example from 10 nm to 100 μm,such as 100 nm or 1 μm. The process for forming the films for theelectronic elements is particularly well suited for very finestructures. Therefore, electronic elements with sizes below 1 μm arepreferred. Examples for electronic elements are field-effect transistors(FET), solar cells, light emitting diodes, sensors, or capacitors. Inoptical devices such as light emitting diodes or light sensors the filmaccording to the present invention serves to increase the reflectiveindex of the layer which reflects light. An example for a sensor is anoxygen sensor, in which the film can serve as oxygen conductor, forexample if a metal oxide film is prepared. In field-effect transistorsout of metal oxide semiconductor (MOS-FET) the film can act asdielectric layer or as diffusion barrier. It is also possible to makesemiconductor layers out of the films in which elemental nickel-siliconis deposited on a solid substrate.

Preferred electronic elements are transistors. Preferably, the film actsas diffusion barrier, contact, liner or capping layer in a transistor.Diffusion barriers of manganese or cobalt are particularly useful toavoid diffusion of copper contacts into the dielectric, often applied asself-forming copper barrier. If the transistor is made of silicon, it ispossible that after deposition of nickel or cobalt and heating somesilicon diffuses into the nickel to form for example NiSi or CoSi₂.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the ¹H-NMR spectrum of compound C-II-1.

FIG. 2 shows the ¹³C-NMR spectrum of compound C-II-1.

FIG. 3 shows the thermogravimetry analysis of compound C-II-2.

FIG. 4 shows the crystal structure of compound C-II-2.

FIG. 5 shows the thermogravimetry analysis of compound C-4.

FIG. 6 shows the crystal structure of compound C-4.

FIG. 7 shows the crystal structure of compound C-1.

FIG. 8 shows the thermogravimetry analysis of compound C-49.

FIG. 9 shows the crystal structure of compound C-49.

FIG. 10 shows the ¹H-NMR spectrum of compound C-58.

FIG. 11 shows the thermogravimetry analysis of compound C-58

FIG. 12 shows the crystal structure of compound C-58.

FIG. 13 shows the thermogravimetry analysis of compound C-59

FIG. 14 shows the crystal structure of compound C-59.

FIG. 15 shows the thermogravimetry analysis of compound C-53

FIG. 16 shows the ¹H-NMR spectrum of compound C-74.

FIG. 17 shows the crystal structure of compound C-74.

FIG. 18 shows the ¹H-NMR spectrum of compound C-75.

FIG. 19 shows the crystal structure of compound C-75.

EXAMPLES

General Procedures

All experiments were carried out under an atmosphere of purifiednitrogen, either in a Schlenk apparatus or in a glovebox. The solventswere dried and deoxygenated by distillation under nitrogen atmospherefrom sodium benzophenone ketyl (tetrahydrofuran) and by an MBraun GmbHsolvent purification system (toluene, pentane, hexane). In the followingdmCh stands for dimethylcyclohexadienyl, C₇H₉ for cycloheptadienyl andC₈H₁₁ for cyclooctadienyl.

Thermogravimetric analysis was performed with about 20 mg sample. It washeated by a rate of 5° C./min in an argon stream. For the differentialscanning calorimetry measurement (DSC) a 20 mg sample was placed in aglass or steal crucible and put in a Mettler TA 8000. The temperaturewas increase from 30 to 500° C. at a rate of 2.5 K/min.

NMR spectra were recorded on a Bruker DRX 400 spectrometer at 400 MHz(¹H) or 101 MHz (¹³C) and a Bruker Avance II 300 at 300 MHz (¹H) or 75MHz (¹³C). All chemical shifts are given in δ units with reference tothe residual protons of the deuterated solvents, which are internalstandards, for proton and carbon chemical shifts. The abbreviations inthe hydrogen nuclear magnetic resonance (¹H-NMR) spectra have theconventional meaning: s for singlet, d for doublet, t for triplet, m formultiplet, br for broad.

A Bruker Vertex 70 spectrometer was used for recording IR spectra.Single crystals of each compound were examined under Paratone oil. Datawere recorded at 100 K on Oxford Diffraction diffractometers usingmonochromated Mo Kα or mirror-focussed Cu Kα radiation. The structureswere refined anisotropically using the SHELXL-97 program as described inActa Crystallographica Section A, volume 64 (2008) pages 112-122.Elemental analyses were performed on a vario MICRO cube elementalanalyzer. Mass spectrometry (MS) was carried out on Finnigan MAT 90 X(EI).

Ligand Synthesis

Potassium Cycloheptadienide L¹

The synthesis is based on the method reported in Bulletin of theChemical Society of Japan, volume 52 (1979) pages 2036-2045. A Schlenkflask was charged with small pieces of potassium (1.04 g, 26.6 mmol, 0.5eq.), THF (10 mL) and Et₃N (5 mL). The reaction mixture was cooled to 0°C. before cycloheptadiene (5.00 g, 53.1 mmol, 1.0 eq.) was slowly added.During the addition, the color of the reaction mixture changed withinminutes from colorless over yellow to red, and the formation of a yellowbrown precipitate was observed. The suspension was warmed up to roomtemperature and stirred for 16 h until all potassium was consumed. Afteraddition of hexane (100 mL), the suspension was cooled to −78° C. andstirred for additional 0.5 h to complete precipitation of the product.The yellow-brown solid was filtered at −50° C., washed with hexane (3×20mL) and dried in vacuo to obtain L¹ as yellow-brown powder in 65% yield(3.55 g, 17.4 mmol).

Potassium Cyclooctadienide L²

The synthesis is based on the method reported in Chemical Society ofJapan, volume 52 (1979) pages 2036-2045. A Schlenk flask was chargedwith small pieces of potassium (0.90 g, 23.1 mmol, 0.5 eq.), THF (10 mL)and Et₃N (5 mL). The reaction mixture was cooled to −20° C. beforecyclooctadiene (5.00 g, 46.2 mmol, 1.0 eq.) was slowly added. The colorof the reaction mixture changed within minutes from colorless to yellow,and an orange precipitate was formed. The suspension was warmed up toroom temperature and stirred for 16 h until all potassium was consumed.After addition of hexane (100 mL) the suspension was cooled to −78° C.and stirred for additional 0.5 h to complete precipitation of theproduct. The yellow-brown solid was filtered at −50° C., washed withhexane (3×20 mL) and dried in vacuo to obtain L² as yellow powder in 69%yield (3.43 g, 16.0 mmol).

Potassium Dimethylcyclohexadienide L³

The synthesis is based on the method reported in Organometallics volume6 (1987), page 1947-1954 and Organometallic Synthesis volume 3 (1986),page 136. To potassium amylate (KO^(i)Pen) (5.55 g, 44.0 mmol, 0.95 eq.)dissolved in hexane (150 mL), dimethylcyclohexadiene (2.60 g, 46.3 mmol,1.00 eq.) was added at −78° C. n-BuLi (30.4 mL, 48.6 mmol, 1.6 M inhexane) was slowly added and the reaction mixture was allowed to warm toambient temperature and stirred for additional 12 h. During this time,the color changed from colorless to yellow. After filtration, the yellowprecipitate was washed extensively with hexane (5×20 mL). The product L³was dried under dynamic vacuum and isolated as a yellow, highlypyrophoric powder. Yield: 5.70 g (39.0 mmol, 84%).

Synthesis of Metal Complexes Example 1

To a stirred solution of Co(acac)₂ (126 mg, 0.49 mmol, 0.5 eq.) in 10 mlTHF a solution of L¹ (200 mg, 0.98 mmol, 1.0 eq.) in 10 ml THF wasslowly added at ambient temperature. Upon stirring, the reaction mixtureat room temperature for 2 h, a brownish precipitate was formed and thecolor of the solution changed from violet to red-orange. The solvent wasremoved in dynamic vacuum and the residue was extracted with pentane(5×4 mL). The red extracts were filtered, dried, and dissolved in asmall amount of hexane (about 1 mL) and cooled to −30° C. The next dayC-II-1 was isolated in 75% yield (84 mg, 0.17 mmol) as redmicrocrystalline solid. C-II-1 can be further purified bysublimation/distillation at 10⁻³ mbar and 120° C.

CHN calculated (%) for C₂₈H₃₆Co₂: C, 68.57, H, 7.40, found: C, 68.44, H,7.428.

EI-MS: M⁺ 490.1 amu.

m.p.: 95° C.

The ¹H-NMR spectra of C-II-1 (C₆D₆, 298 K) is depicted in FIG. 1. The¹³C-NMR (C₆D₆, 298 K) is depicted in FIG. 2.

Example 2

To a stirred solution of Co(acac)₂ (439 mg, 1.71 mmol, 0.5 eq.) in 20 mlTHF a solution of L³ (500 mg, 3.42 mmol, 1.0 eq.) in 10 ml THF was addedslowly. After stirring for 1 h the precipitate was filtered off and thedark brown solution was evaporated to dryness. Addition of 10 ml hexanegave an orange precipitate, which was dissolved in a mixture of THF(some drops) and hexane (ca. 2 mL). The orange-red solution was filteredand kept at −30° C. to give red crystals of C-II-2.C₆H₁₄ which wereisolated in 53% yield (248 mg, 0.45 mmol). Pure C-II-2 was obtainedafter recrystallization from Et₂O.

CHN after recrystallization from Et₂O calculated (%) for C₃₂H₄₄Co₂: C,70.32, H, 8.11, found: C, 70.16, H, 8.105.

¹H NMR (C₆D₆, 298 K): 6=4.76 (4H CH s), 4.57 (2H CH s), 4.52 (2H CH s),4.43 (2H CH₂ s), 3.58 (4H CH s), 2.31 (2H CH s), 2.29 (2H CH s), 1.47(6H CH₃ s), 1.16 (6H CH₃ s), 0.85 (6H CH₃ s), 0.46 (6H CH₃ s) ppm.

¹³C{¹H} NMR (C₆D₆, 298 K): δ=91.8 (CH), 90.9 (CH), 82.2 (CH), 79.5 (CH),78.2 (CH), 65.0 (CH), 60.3 (CH), 59.8 (CH), 56.1 (CH), 52.1 (CH) 34.7(C), 33.4 (C), 32.9 (CH₃), 32.4 (CH₃), 31.8 (CH₃), 29.5 (CH₃) ppm.

m.p.: 165-167° C.

EI-MS: M⁺ 546.2 amu.

The thermogravimetry analysis of C-II-2 is depicted in FIG. 3. Derivingfrom the thermogravimetry analysis, the sample has lost 73.3% of itsmass at 500° C.

Crystals of C-II-2.C₆H₁₄ suitable for X-ray diffraction were obtainedfrom THF/n-hexane solution at −30° C. The crystal structure is shown inFIG. 4.

Example 3

To a stirred solution of Ni(acac)₂ (588 mg, 2.29 mmol, 1.0 eq.) in 20 mlTHF a solution of L² (1.00 g, 4.58 mmol, 1.0 eq.) in 20 ml THF wasslowly added. Immediately the color of the solution changed from greento dark red. The reaction mixture was stirred at room temperature for 2h. The solvent was removed in dynamic vacuum and the residue wasextracted with hexane (5×10 mL). The red extracts were filtered,evaporated, and the residue was dissolved in 2 ml Et₂O. After keepingthe solution at −30° C. C-4 crystallized as yellow plates, which wereisolated in 51% yield (320 mg, 1.18 mmol). C-4 can be further purifiedby sublimation at 10⁻³ mbar and 100° C.

CHN calculated (%) for C₁₆H₂₂Ni: C, 70.38, H, 8.12, found: C, 70.44, H,7.915.

EI-MS: M⁺ 272.1 amu.

¹H NMR (C₆D₆, 298 K): δ=5.32 (1H CH, br s), 4.52 (3H CH br s), 2.29 (2HCH₂ br s), 1.73 (2H CH₂ br s), 1.08 (1H CH₂ m), 0.74 (1H CH₂ m) ppm.

¹³C{¹H} NMR (C₆D₆, 298 K): δ=65.5 (CH), 64.3 (CH), 26.7 (CH₂), 18.1(CH₂) ppm.

The thermogravimetry analysis of C-4 is depicted in FIG. 5. Derivingfrom the thermogravimetry analysis, the sample has lost 66.9% of itsmass at 500° C. Crystals of C-4 suitable for X-ray diffraction wereobtained from Et₂O solution at −30° C. The crystal structure is shown inFIG. 6.

Example 4

To a stirred solution of NiCl₂(dme) (376 mg, 1.71 mmol, 1.0 eq.) in 20ml THF a solution of L³ (1.00 g, 3.42 mmol, 1.0 eq.) in 20 ml THF wasadded slowly. Immediately the color of the solution changed from greento dark red. The reaction mixture was stirred at room temperature for 2h. The solvent was evaporated and the residue was extracted with hexane(5×10 mL). The red extracts were filtered, evaporated and dried beforethe residue was dissolved in a 2 ml hexane. The solution was stored at−30° C. to give C-1 as brown crystals, which were isolated in 52% yield(241 mg, 0.88 mmol). C-1 can be further purified by sublimation at 90°C. at 10⁻³ mbar.

CHN calculated (%) for C₁₆H₂₂Ni: C, 70.38, H, 8.12, found: C, 69.27, H,8.595.

¹H NMR (300 MHz, C₆D₆, 298 K): δ=5.21 (4H CH dd, J=8.14 Hz, J=5.49 Hz),4.57 (2H CH t, J=5.49 Hz), 4.44 (4H CH d, J=7.57 Hz), 1.09 (6H CH₃ s),1.06 (6H CH₃ s) ppm.

¹³C{¹H} NMR (75.5 MHz, C₆D₆, 298 K): δ=106.8 (CH), 98.6 (CH), 63.8 (CH),36.9 (C), 34.0 (CH₃), 31.8 (CH₃) ppm.

EI-MS: M⁺ 272.1 amu.

m.p.: 79° C.

Crystals of C-1 suitable for X-ray diffraction were obtained from Et₂Osolution at −30° C. The crystal structure is shown in FIG. 7.

Example 5

To a stirred solution of [CoCl(PMe₃)₃] (148 mg, 0.458 mmol, 1.0 eq.) inTHF (10 mL) a suspension of L² (100 mg, 0.458 mmol, 1.0 eq.) in THF (10mL) was added slowly. The color of the solution changed immediately fromdark blue to red-brown. The reaction mixture was stirred at ambienttemperature for 24 h. The solvent was removed in dynamic vacuum and thered-brown residue was extracted with hexane (4×5 mL). After removing thesolvent in dynamic vacuum, the orange-red residue was dissolved in asmall amount of Et₂O (ca. 1 mL) filtered. The solution was storedovernight at −30° C. to give C-49 as brown crystals, which were isolatedin 78% yield (142 mg, 0.36 mmol). C-49 can be further purified bysublimation at 60° C. at 10⁻³ mbar.

CHN calculated (%) for C₁₇H₃₈CoP₃: C, 51.78, H, 9.71, found: C, 51.82,H, 10.092.

EI-MS: M⁺ 394.1 amu; 318.1 (M⁺-PMe₃).

¹H NMR (C₆D₆, 298 K): δ=6.32 (1H), 5.37 (1H), 4.64 (1H), 3.34 (1H), 2.71(1H), 2.13 (2H), 1.95 (1H), 1.83 (1H), 1.56 (2H), 1.05 (27H PMe₃) ppm.

¹³C{¹H} NMR (C₆D₆, 298 K): δ=141.7 (CH), 116.9 (CH), 68.3 (CH), 51.4(CH), 50.3 (CH), 35.8 (CH₂), 31.9 (CH₂), 26.0 (CH₂), 22.6 (PMe₃) ppm.

³¹P{¹H} NMR (C₆D₆, 298 K): δ=0.06 (PMe₃) ppm.

m.p.: 104° C.

The thermogravimetry analysis of C-49 is depicted in FIG. 8. Derivingfrom the thermogravimetry analysis, the sample has lost 70.6% of itsmass at 500° C. Crystals of C-49 suitable for X-ray diffraction wereobtained from Et₂O solution at −30° C. The crystal structure is shown inFIG. 9.

Example 6

To a stirred solution of C-49 (5.00 g, 12.68 mmol, 1.0 eq.) in pentane(30 mL) depe (2.62 g, 12.68 mmol, 1.0 eq.) was added at ambienttemperature. The color of the solution changed within 1 h from dark redto a brighter red. The reaction mixture was stirred at ambienttemperature for 5 days before the solvent was removed in dynamic vacuum.The red residue was solved in a minimum amount of Et₂O (ca. 5 mL),filtered and stored overnight at −30° C. to give C-58 as red crystals,which were isolated in 88% yield (5.00 g, 11.16 mmol).

CHN calculated (%) for C₂₁H₄₄CoP₃: C, 56.25, H, 9.89, found: C, 56.55,H, 9.854.

The ¹H-NMR spectra of C-58 (C₆D₆, 298 K) is depicted in FIG. 10.

³¹P{¹H} NMR (C₆D₆, 298 K): δ=73.8 (depe), 70.5 (depe), −13.2 (PMe₃) ppm.

m.p.: 74-76° C.

The thermogravimetry analysis of C-58 is depicted in FIG. 11. Derivingfrom the thermogravimetry analysis, the sample has lost 87.17% of itsmass at 500° C. Crystals of C-58 suitable for X-ray diffraction wereobtained from Et₂O solution at −30° C. The crystal structure is shown inFIG. 12.

Example 7

A stirred solution of C-58 (5.00 g, 11.16 mmol, 1.0 eq.) in pentane (30mL) was cooled to 0° C. and CO was passed through the solution over 6 h.The color of the solution changed from red to an orange red within 30min. The solvent was removed in dynamic vacuum and the residue wassolved in a minimum amount of Et₂O (ca. 3-5 mL). The residue wasdissolved in a minimum amount of Et₂O (ca. 0.5 mL), filtered and stored3 days at −30° C. to obtain C-59 as orange crystals in quantitativeyields.

C-59 can be further purified by sublimation at 5·10⁻² mbar and 100° C.

CHN calculated (%) for C₁₉H₃₅CoOP₂: C, 57.00, H, 8.81, found: C, 56.91,H, 8.709.

¹H NMR (C₆D₆, 298 K): δ=6.62 (1H), 5.34 (1H), 4.54 (1H), 3.82 (1H), 3.23(1H), 3.05 (1H), 2.49 (1H), 2.31 (1H), 2.15 (1H), 1.72 (1H), 1.47 (5H),1.16 (10H), 0.96 (4H), 0.59 (6H) ppm.

¹³C{(H} NMR (C₆D₆, 298 K): δ=205.3 (CO), 140.1 (CH), 118.9 (CH), 75.6(CH), 58.8 (CH), 54.5 (CH), 37.0 (CH₂), 30.5 (CH₂), 30.4 (CH₂),26.3-25.5 (m, CH₂, CH₂-DEPE), 19.7 (CH₂-DEPE), 8.6 (CH₃-DEPE), 8.2(CH₃-DEPE) ppm.

³¹P{¹H} NMR (C₆D₆, 298 K): δ=80.8 (depe), 75.8 (depe) ppm.

m.p.: 73° C.;

The thermogravimetry analysis of C-59 is depicted in FIG. 13. Derivingfrom the thermogravimetry analysis, the sample has lost 83.26% of itsmass at 500° C. Crystals of C-59 suitable for X-ray diffraction wereobtained from Et₂O solution at −30° C. The crystal structure is shown inFIG. 14.

Example 8

Through a stirred solution of C-49 (4.50 g, 11.16 mmol, 1.0 eq.) inpentane (30 mL) CO was passed over 6 h at 0° C. The color of thesolution changed from red to orange-red within 30 min. The solvent wasremoved in dynamic vacuum to give C-53 as a red oily liquid in 95% yield(3.16 g, 10.60 mmol). C-53 can be further purified by distillation at50-75° C. and 4·10⁻² mbar. C-53 can be obtained as an orangemicrocrystalline solid by cooling the oily liquid with liquid nitrogenand thawing to ambient temperature.

¹H NMR (C₆D₆, 298 K): δ=6.29 (1H), 5.18 (1H), 4.68 (1H), 4.26 (1H), 3.30(1H), 2.73 (1H), 2.08 (1H), 1.94 (1H), 1.76 (1H), 1.39 (1H), 1.19 (1H)0.90 (9H PMe₃, d (J=9 Hz)) ppm.

¹³C{(H} NMR (C₆D₆, 298 K): δ=137.5 (CH), 121.7 (CH), 83.0 (CH), 69.7(CH), 61.1 (CH), 35.2 (CH₂), 29.0 (CH₂), 25.2 (CH₂), 19.4 (PMe₃, d (J=27Hz)) ppm.

³¹P{¹H} NMR (C₆D₆, 298 K): δ=18.0 (PMe₃) ppm.

IR (KBr, Nyol): 1971 cm⁻¹ (CO), 1909 cm⁻¹ (CO).

m.p.: room temperature (˜25° C.).

The thermogravimetry analysis of C-53 is depicted in FIG. 15. Derivingfrom the thermogravimetry analysis, the sample has lost 77.94% of itsmass at 500° C.

Example 9

To a stirred solution of C-49 (0.296 g, 0.75 mmol, 1.0 eq.) in Et₂O (10mL) dmpe (0.113 g, 0.75 mmol, 1.0 eq.) was added at ambient temperature.The color of the solution changed from dark red to a brighter red within1 h. The reaction mixture was stirred at ambient temperature for 2 hbefore the solvent was removed in dynamic vacuum. The red residue wasdissolved in a minimum amount of Et₂O (ca. 0.5 mL), filtered and storedovernight at −30° C. to obtain C-74 as red crystals, which were isolatedin 95% yield (0.279 g, 0.71 mmol).

CHN calculated (%) for C₁₇H₃₆CoP₃: C, 52.04, H, 9.25, found: C, 51.55,H, 9.211.

The ¹H-NMR spectra of C-74 (C₆D₆, 298 K) is depicted in FIG. 16.

³¹P{¹H} NMR (C₆D₆, 298 K): δ=54.3 (dmpe), 51.1 (dmpe), −10.1 (PMe₃) ppm.

Crystals of C-74 suitable for X-ray diffraction were obtained from Et₂Osolution at −30° C. The crystal structure is shown in FIG. 17.

Example 10

A stirred solution of C-74 (0.20 g, 0.51 mmol, 1.0 eq.) in Et₂O (5 mL)was pressurized with 7 bar CO. The color of the solution changedimmediately from red to orange. The pressure was carefully releasedbefore the solvent was removed in dynamic vacuum. The residue wasdissolved in a minimum amount of Et₂O (ca. 0.5 mL), filtered and stored2 days at −30° C. to obtain C-75 as orange crystals in quantitativeyields.

CHN calculated (%) for C₁₅H₂₇CoOP₂: C, 52.33, H, 7.91, found: C, 51.98,H, 7.933.

The ¹H-NMR spectra of C-75 (C₆D₆, 298 K) is depicted in FIG. 18.

³¹P{¹H} NMR (C₆D₆, 298 K): δ=57.3 (dmpe), 51.6 (dmpe) ppm.

Crystals of C-75 suitable for X-ray diffraction were obtained from Et₂Osolution at −30° C. The crystal structure is shown in FIG. 19.

1: A process comprising bringing a compound of general formula (I) intoa gaseous or aerosol state

and depositing the compound of general formula (I) from the gaseous oraerosol state onto a solid substrate, wherein: R, at each instance, isindependently hydrogen, an alkyl group, an alkenyl group, an aryl groupor a silyl group, p is 1, 2 or 3, M is Ni or Co, X is a σ-donatingligand which coordinates M, wherein if present at least one X is aligand which coordinates M via a phosphorus or nitrogen atom, m is 1 or2 and n is 0 to
 3. 2: The process according to claim 1, wherein M is Coin the oxidation state +1 or Ni in the oxidation state +2. 3: Theprocess according to claim 2, wherein M is Co, m is 1, and all X areneutral σ-donating ligands. 4: The process according to claim 2, whereinM is Ni, m is 2, and n is
 0. 5: The process according to claim 1,wherein R, at each instance, is independently hydrogen, methyl, ethyl oriso-propyl. 6: The process according to claim 1, wherein the depositedcompound of general formula (I) is exposed to a reducing agent. 7: Theprocess according claim 1, wherein a sequence of depositing the compoundof general formula (I) onto a solid substrate and decomposing thedeposited compound of general formula (I) is performed at least twice.8: A compound of general formula (I),

wherein: R, at each instance, is independently hydrogen, an alkyl group,an alkenyl group, an aryl group or a silyl group, p is 1, 2 or 3, M isNi or Co, X is a σ-donating ligand which coordinates M, wherein ifpresent at least one X is a trialkylphosphane or a ligand whichcoordinates M via a nitrogen atom, m is 1 or 2 and n is 0 to
 3. 9: Thecompound according to claim 8, wherein M is Co, m is 1, and all X areneutral σ-donating ligands. 10: The compound according to claim 8,wherein M is Ni, m is 2, and n is
 0. 11: The compound according to claim8, wherein R, at each instance, is independently hydrogen, methyl,ethyl, iso-propyl, or tert-butyl.
 12. (canceled)